Quick-release valve for air-brakes



sheet 1.

. (No Model.) 4

H. R. MASON. QUICK RELEASE VALVE PoR AIR BRAKES.

Patented Mar. 14, 1893.

(No Model.) v2 sheets-sheet 2.

, H. R. MASON. QUICK RELEASE VAL-VE POR AIR BRAKES. No. 493,436.Patented Mar. 14, 1893.

UNITED STATES PATENT OFFICE..

HARRY R. MASON, OF CHICAGO, ILLINOIS.

QUICK-RELEASE VALVE FOR AIR-BRAKES.

SPECIFICATION forming part of Letters Patent No. 493,436, dated March14, 1893.

Application lcd February 11, 1 892. Serial No. 421.177. (No model.)

To all whom t may concern:

Be it known that I, HARRY R. MASON, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois,haveinvented a new and useful Improvement in Quick-Release Valves forAir-Brakes, of which the following is a specification.

Myinvention relates to an improvement in quick-release valve-mechanismoperating, independent of the triple-valve, to release brakes by ventingair from the brake-cylinderwhen pressure is raised inthe train-pipe.

Two patents for quick-release valves for air-brakes, numbered 467,038and 467,111, respectively, were granted to me January 12, 1892; andy mypresent object is to provide certain changes in the construction of thevalvemechanisms described and claimed in those patents, to the `end ofimproving upon the same and producing what I believe to be a moredurablevalve device, for the same purpose.

In the drawings: Figure 1 is abroken plan view, showing my improvementin connection With other features of au air-brake system forming part ofthe equipment of a railwaycar; and Fig. 2, an enlarged broken section ofmy improved device, the section being taken on line 2 of Fig. 1 andviewed in the direction of the arrow.

T is a main train or brake-pipe; W, an auxiliary reservoir; Y, atriple-valve; and Z, a brake-cylinder. These devices communicate throughpipes, as shown, and as they are of well-known construction and performfunctions Well-known in the art, they require no detailed description inthe present connection.

A is the valve-casing of my improved quickrelease valve device. In thecasing is a chamber formed with an enlarged part, B, and reduced part,B', said enlarged and reduced parts being virtually twointer-communicating chambers. The chamber B communicates through apassage, and pipe t, with the train pipe of the brake system. In thechamberB is a valve or piston, s, upon a stem s',which extendslongitudinally and centrally through the chamber B. The piston s fitsclosely, and4 moves against, the circular wall of the chamber B, toprevent leakage between oppcsite sides of the piston. Extending from thechamber B t0 thechamber B is a passage,

r, cored or drilled in the casing A. The piston s, under pressureexerted against it from the train pipe through the passage t, is forcedto the position shown in Fig. 2, wherein it abuts against the end of thechamber-B. The passage r enters the chamber B just forward of the pistons,when the latter is driven backward to the said position. In thepassage r is a chamber, 0*', for a check valve, r2, controlled by aspring, r3, of slight resistance, which seats the said valve normally inthe direction of the chamber B. Communicating with the chamber B',through passages p, is a reservoir chamber, C. The function of thechamber C is to co-operate with the chamber B' in the sense of affordinga larger receiver for air under pressure than, owing to the nature ofthe construction of the device, can be afforded by the chamber B alone.To allintents and purposes, therefore, the chambers B and C are one. Thestem s' reciprocates through a guide,p', between the chambers B and C.Extending from the chamber B' at the location shown is an exhaustpassage, o, communicating with the outside air. In line with the port ofthe passage o, in the chamlber B', is the port of a passage, n,affording communication between the chamber B and a chamber, D. Thechamber D is closed by a flexible diaphragm, m, from the center of whichextends a stem, m. The diaphragm m divides the chamber D from a chamber,E, which latter communicates through au opening, Z, with the outsideair. On the side of the chamber E opposite the diaphragmchamber D is achamber or passage, F, which is divided from the chamber E by a flexiblediaphragm, m2. The stem m extends ceutrally through the diaphragm m2 andthrough a guide, 7c', in the opposite side of the chamber F. Beyond thebearing It is a valve-seat, 7a2, through which the stem m' extends, andat which it is provided with a valve, 'm3, which seats in the directionof the chamber F. Beyond the said valve-seat 7a2 is a guide, 7a3, forthe end portion of the stem m'. On the stem m. and confined between theguide k3 and valve m3 is a spring, m4. Beyond the guide k3 is a passage,F', which communicates through a suitable pipe Z with thebrake-cylinder, at the same end of the latter as that with which thetriple valve mechanism communicates.

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Extending from the chamber F is an outlet, k, which leads to the outsideair. Through the guides la and k3 are openings, so that the chamber Fand passage F form a continuous outlet passage from the brake-cylinderto the outside air controlled by the check-valve m3. Upon the stem s inthe chamber B is a slidevalve, l1, which. is located between stops s2and s3 on the said stem, and is a tride shorter than the distancebetween those stops, in order to permit the stem s to have limited.independent motion with relation to the slidevalve. The slide-valve isadapted to afford alternate communication between the chamber B andpassage fn, and between the passage n and outlet o, and is held to itsseatby a spring, h', interposed between the slide valve and stem s'.Extending through the slide-valve his a small outlet passage, h2, havinga valve-seat, h3, formed therein, for a graduating-valve, q. The gradmating-valve is upon a stem,g, connected to and movable with the stem s.The passage affords communication between the chamber B and outside-airwhen the valve q is opened. The valve q is closed by movement of thestem s in the direction of causing its stop s2 to engage theslide-valve, and opened by movement of the stem s in the contrarydirection.

In operation when the train pipe T is filled with pressure to releasebrakes, air enters the chamber B from the train pipe through the pipe tand forces the piston s to the position shown in Fig. 2. This backwardmovement of the piston s opens communication between the train-pipe andthe passage r, closes communication between the passage n and outletpassage o, closes the valve q, and opens communication between thechambers B and D through the passage n. Air from the chamber B flowsthrough the passage r, opens the check-valve r2, against the slightresistance of' the spring r3, and iiows into the chamber B', filling thelatter, the chamber C and the diaphragm chamber D. The pressure thusexerted against the diaphragm m drives the latter outward, carrying withit the stem m against the resistance of the spring m4, and opens thevalve m3, to afford an unobstructed passage for air from thebrake-cylinder to the outside atmosphere through the outlet 7c. Whenpressure is vented from the train pipe, and consequently from thechamber B, the superior pressure then existing in the expansion chambersB' and C forces the piston s forward, closing the passage r, anddragging the slide-valve h, to cause the latter to close communicationbetween the chamber B and passage n, and open communication between thepassage n and outside air, to vent pressure from the chamberD. As beforedescribed when in its backward position, shown in Fig. 2, the piston sabuis against the end of the chamber B', in order therefore that thepressure exerted from the chamber B may be against the entire area ofthe rear surface of the piston s,a recess, s", is provided upon` therear face of the piston at the edge of the wall of the chamber B for thepassage of air. The forward movement, described, of the piston s and itsstem s', opens the graduatingvalve q, and permits air to escape from thechambers B and C through the passages h2 and o. When the pressure inthose chambers is thus reduced slightly below the trainpipe pressure,the latter moves the piston s backward until the stop s2 engages theslidevalve and the valve q is closed. Any further reduction in trainpipepressure will cause the piston s to be driven forward until the pressurein the chambers B and C is again reduced below the train-pi pe pressure,when the valve q will be closed again. When pressure is vented from thechamber D, as described, the spring m4 moves the stem m and diaphragmm', and closes the Valve m3, thus shutting off the escape of pressurefrom the brake-cylinder to the outside air.

In practice the exposed surface of the flexi- I ble diaphragm m islarger than that of the diaphragm m2, so that the escaping pressure fromthe brake-cylinder exerted against the diaphragm m2, supplemented by theforce of the spring m4, will not be sufficient to counteract thepressure exerted against the diaphragm m from the chamber D, and toclose the valve m3. The spring m4 may be `made of any desiredresistance, so that it may bej ust capable of moviugthestemm anddiaphragme m m2 when the chamber D is exhausted of pressure, or wherebyit may raise the stem and close the valve m when pressure is reduced toonly a limited extent in the chamber D.

It is desirable, to obtain the best results in the use of my improvedmechanism, that it shall operate to open or shut off the escape ofpressure from the brake cylinder through the passage F F and 7c, inadvance of the operation of the triple-valve mechanism.

M y im proved quick release mechanism may be constructed to operateunder very slight variations in train pipe pressure, depending only uponthe frctional resistance of the piston s against the wall of the chamberB and the slide valve h on its seat. Owing to the construction shown anddescribed no stuiing boxes are required to prevent leakage. This is anadvantage for the reason that it is dillicult to prevent wear andconsequent leakage of a stuffing box, and at the same time to preventthe stuiing box, and stem passing through it, from presenting morefriction than is desirable.

I have shown a pressure-retainingvalve, G, at the outlet opening 7c, forthe purpose of holding back a certain amount of pressure when it is notdesired that all the pressure shall be ven ted from the brake-cylinder.The function and operation of the pressure-re taining valve arewell-known in the art, and it requires no detailed description in thepresent connection.

While I have shown and described acheck- IOO valve r2 in the passage r,this may, if desired, be omitted, and the passage r may be sufficientlysmall to prevent a material retrogression of pressure from the chamber Bto the train-pipe before the piston s is moved.

Though I prefer to provide the twotiexible diaphragms m and m2, with achamber E between them open to the surrounding atmosphere, the diaphragmm2 and chamber E, could, if desired, be dispensed with, and the devicestill be operative.

Whilel have shown and described the valve s as a piston, it may be anyform of abutment or diaphragm which will be movable under differentialpressure, and by its movement govern the operation of the other valvcmechanism as set forth.

I do not confine my invention to the use of the exact form of valvesemployed, as they may be changed in character without changing theirfunctions. The general form of the whole device may also be changedwithout departing from the spirit of my invention as defined by theclaims.

What I claim as new, and desire to secure by Letters Patent, is-

I. In combination with the train-pipe and brake-cylinder of abrake-system, a quick-release valve-device, independent of thetriplevalve mechanism, provided with a brake-cylinder exhaust-passage, avalve governing the exhaust through said passage controlled by adiaphragm movable by dierential pressure, an expansion chamber, andvalve mechanism interposed between the train pipe and expansion chamber,and operated by differential pressure, to direct pressure to or vent itfrom one side of said diaphragm, whereby the valve .in saidexhaust-passage is closed when the train-pipe pressure is reduced andopened when said pressure is raised, substantially as and for thepurpose set forth.

2. In combination with the train-pipe and brake-cylinder of abrake-system, a quick-release valve-device, independent of thetriplevalve mechanism, provided with a brake-cylinder exhaust-passage, avalve governing the exhaust through said passage, a diaphragm connectedwith said valve, moved in one direction, by the force of air-pressuredirected against it, to open said valve, a spring acting, counter tosaid air-pressure, against the diaphragm, when the air-pressure isreleased,

to close said valve, an expansion chamber, and valve mechanisminterposedbetween the train-pipe and expansion-chamber operated by diierentialpressure to direct air to or vent it from one side of said diaphragm,whereby the valve in said exhaust-passage is opened when the train-pipepressure is increased, and closed when the train-pipe pressure isreduced, substantially as and for the purpose set forth.

3. In combination with the train-pipe and brake-cylinder of abrake-system, a quick-reiease valve-device, independent of thetriplevalve mechanism, provided with an expansion-chamber communicatingwith the trainpipe, a brake-cylinder exhaust passage, a diaphragmchamber, a passage between the said expansion and diaphragm-chambers, adiaphragm-chamber exhaust passage, a valve governing the exhaust throughthe brake-cylinder exhaust passage, controlled by movement of adiaphragm at the said diaphragmchamber, valve -mechanism governingcommunication between the expansion and diaphragm chambers and betweenthe diaphragm chamber and outside air, the said valve-mechanism beingconnected with and operated by a piston movable by differential pressureand interposed between the train-pipe and expansion-chamber,substantially as described.

4. In a brake-system, the combination, with the train-pipe andbrake-cylinder, of quickrelease valve-mechanism, independent of thetriple valve, comprising valve casing, provided with an expansionchamber communicating with the train-pipe to receive pressure therefrom,an exhaust passage from the brakecylinder to the outside air, a valvegoverning the exhaust through said passage, controlled byvalve-mechanism having a piston movable by differential pressure andinterposed between the train-pipe and expansion chamber, a small passagefor the escape of pressure from the expansion chamber to the outsideair, and a valve governing the escape of pressure through said smallpassage, controlled by the said interposed movable piston, substantiallyas and for the purpose set forth.

HARRY R. MASON.

In presence of- M. J. FRosr, W. N. WILLIAMs.

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